Date of Submission


Document Type


Degree Name

Master of Science in Cellular and Molecular Biology


Biology and Environmental Sciences


Dr. Anna Kloc

Committee Member

Dr. Eva Sapi

Committee Member

Dr. Nikolas Stasulli


Theiler’s encephalomyelitis virus, Recombinant deletion viruses, Cloning strategy, Viral persistence


Myocarditis, Borna disease virus, 5' Untranslated regions, Virus replication, Internal ribosome entry sites, RNA


Myocarditis, Borna disease virus, Viruses--Reproduction, Heart cells, RNA, Cell culture


Viral myocarditis is described as the inflammation of the heart muscle, and it is a common condition that can affect the heart. It is estimated that myocarditis causes 1.5 million deaths annually. In mice, Theiler’s encephalomyelitis virus (TMEV) is a common cause of myocarditis. This non-attenuated virus can be used in a cell culture model system to study viral replication and persistence. These processes have been linked to the severity of the heart damage, which in most clinical scenarios, can lead to dilated cardiomyopathy. The 5’ untranslated region (5‘UTR) found in the viral genome of TMEV is well known to control viral replication. In particular, the internal ribosome entry site (IRES) elements of the 5'UTRs are involved in the replication and translation regulation. In patients suffering from chronic myocarditis, the IRES has been found to acquire deletions, suggesting a strong correlation between mutations, viral persistence and pathogenicity. Similarly, deletions in the 5’UTR secondary loop regions have been linked to increased viral infections. The goal of the research project is to study the 5’UTR region of TMEV to understand its role in viral replication and persistence. During the course of this research project, I designed a cloning strategy to generate four recombinant deletion viruses to test their ability to infect primary cardiac cells. The designed deletions maintained the secondary RNA structures loop, which is important for the recognition of the virus by the host’s immune system. In summary, this research will help to better understand the role of 5’UTR elements in regulation of viral replication and its contribution to myocarditis.